High electron mobility transistor having a boron nitride alloy interlayer and method of production

Abstract

A semiconductor device includes a III-nitride buffer layer and a III-nitride barrier layer. A boron nitride alloy interlayer interposed between the III-nitride buffer layer and the III-nitride barrier layer. A portion of the III-nitride buffer layer includes a two-dimensional electron gas (2DEG) channel that is on a side of the III-nitride buffer layer adjacent to the boron nitride alloy interlayer.

What is claimed is: 
     
       1. A method for forming a semiconductor device, the method comprising:
 forming a gallium nitride buffer layer; 
 forming an aluminum nitride interlayer on the gallium nitride buffer layer; 
 forming a boron aluminum nitride interlayer on the aluminum nitride interlayer; and 
 forming an aluminum gallium nitride barrier layer directly on the boron aluminum nitride interlayer, 
 wherein a portion of the gallium nitride buffer layer includes a two-dimensional electron gas, 2DEG, channel that is adjacent to the aluminum nitride interlayer, and 
 wherein a conduction band minimum of the aluminum gallium nitride barrier layer is higher than a conduction band minimum of the gallium nitride buffer layer, a conduction band minimum of the aluminum nitride interlayer and the boron aluminum nitride interlayer are higher than the conduction band minimum of the gallium nitride buffer layer, and there is a polarization difference between the aluminum nitride interlayer and the gallium nitride buffer layer. 
 
     
     
       2. The method of  claim 1 , further comprising:
 forming a III-nitride cap layer on the aluminum gallium nitride barrier layer. 
 
     
     
       3. A semiconductor device, comprising:
 a gallium nitride buffer layer, a portion of which includes a two-dimensional electron gas, 2DEG, channel; 
 an aluminum nitride interlayer arranged on the gallium nitride buffer layer; 
 a boron aluminum nitride interlayer arranged on the aluminum nitride interlayer; and 
 an aluminum gallium nitride barrier layer arranged directly on the boron aluminum nitride interlayer, wherein the portion of the gallium nitride buffer layer including the 2DEG channel is on a side of the gallium nitride buffer layer adjacent to the aluminum nitride interlayer, and 
 wherein a conduction band minimum of the aluminum gallium nitride barrier layer is higher than a conduction band minimum of the gallium nitride buffer layer, a conduction band minimum of the aluminum nitride interlayer and the boron aluminum nitride interlayer are higher than the conduction band minimum of the gallium nitride buffer layer, and there is a polarization difference between the aluminum nitride interlayer and the gallium nitride buffer layer. 
 
     
     
       4. The semiconductor device of  claim 3 , further comprising:
 a III-nitride cap layer arranged on the aluminum gallium nitride barrier layer.